This invention relates to a method of coating a glass surface with a heat-reflecting metal oxide film comprising titanium oxide. This method is particularly suitable for application to the production of a heat-reflecting glass plate.
The use of heat-reflecting glass plates as window panes or wall panels in buildings and vehicles has been prevailing with the objects of avoiding unwanted rise in the interior temperature and reducing the heat load on the interior air conditioning.
A heat-reflecting glass plate is obtained by coating one side of a glass plate with a certain metal oxide film such as of cobalt oxide, chromium oxide, iron oxide, nickel oxide, tin oxide and/or titanium oxide. The coating is accomplished by heating a solution of a metal salt (or metal salts) applied onto a glass surface to cause thermal decomposition of the metal salt(s) to metal oxide(s), for example, by spraying the solution onto a heated glass surface. At present, typical examples of titanium compounds used to form titanium oxide on a glass surface are alkyl titanates, titanium acylates, tetrachlorotitanium and titanium tetraoctyleneglycoxide. However, a titanium oxide coating, or a metal oxide coating comprising a large amount of titanium oxide, produced through thermal decomposition of a conventionally utilized titanium compound is unsatisfactory in its reflectivity to thermal rays and inferior to other kinds of metal oxide coatings in adhesion to the glass surface.